Contact apparatus for electric igniters.



PATENTED MAR. 1908.

KRANNIGHFELDT. CGNTACT APPARATUS FOR'ELEGTRIG IGNITBRS.

APPLICATION FILED DEO.16.1905.

Nov. 882,394.

UNITED sTAras.

JO'HANN KRAN'NICHFELDT,"()F COLOGNE, GERMANY.

CONTACT APPARATS FOR ELECTRIC IGNITERS.

Specification of Letters Patent.

Patented March 17, 1908.

Application filed December 16, 1905. Serial No. 292,018.

To all whom it 'may concern.:

Be it known that l, JOHANN KRANNICH- FELDT, a subject of the Kingof Prussia, residing in (Qologne-oii-thc-Rhine, in the German Empire, have invented new and useful Improvements in Contact Apparatus for Electrical lgniters, of which the following is a specification My present invention relates to magnetic induction apparatus or dynamo apparatus for 'firing electric igniters such as are used for blasting purposes in connection with mines, and the object of my improvements is firstly to prevent the circuit of the igniters i being closed until suflicient current isv generated to fire all the igniters and secondly to close the circuit of 'the igniters-witl'iout occasioning vibrations of any kind.

In the accompanying drawings illustrating the invention: Figure 1 isv an elevation showing one way of closing the circuit of thc igniters by the action of a centrifugal piece, Fig. 2 is a side elevation. of the same.

In the form shown in Figs. 1 `and 2, the armature spindle 1 is put into rapid rotation by depressing the rack 2 and by intervention of the toothed wheels 3, 4, 5. On spindle 1 is mounted a disk 6, carrying a centrifugal piece 8, terminating in a spring 7, pivot mounted at 9, and normally maintained within the circumference of the disk, by a spring 10. In the plane of the centrifugal piece 8 is a latch 11, which, at 12, is piyoted to the casing 13 of the apparatus, and, whose free end serves to hold the contact p'iece, 14, which is in the form of a spring, at a slight distance from the contact piece 15. When, by a strong depression of the rack 2 the disk 6 is rotated rapidly enough, the centrifugal piece 8 acted upon by centrifugal power, will with its spring 7 strike the lower end of latch 11, so as to set free the contact 14, which, thereupon, will be brought into contact with the contact piece 15 by the action of the spring 16, while the latch 1l, whose upward motion is limited by a striking piece 17, will fall upon the contact piece 14 and remain lying there until the circuit is interrupted.

To insure that the circuit of the igniting apparatus is interrupted before the rack 2 can again be operated for a fresh set ofi', it will be convenient to provide a lever 20, fulcrumed at 19 and carrying a pin 18 and whose lower end is operated by a key 22, which also serves for releasing the snapblock 21 of the rack 2, so that the Contact l piece 14 may be separated from the contact piece 15, thereby enabling the latch l1 lagain to fall behind andl hold back the contact piece 14.

The operation of the apparatus is as follows z-ln the position of rest, with the igniting circuit closed, the contact piece 14 bears against the contact piece 15 and the latch 11 upon the piece 14 and the rack 2 is in its lowcrmost position and locked by the bolt 21. To set the apparatus the key 22 is turned. towards the left so as to cause the lever 20 to push the contact piece 14 away from the conand holds, said contact piece 14. This enables the rack 2 to be lifted and depressed in order to turn the toothed wheel 3 in engagement therewith, and in the.` lowest position the bolt 21 will again fall into the' notch of said rack 2 and lock the same. Now, if the 'rack is pushed down sufliciently rapidly or with sufficient force, the centrifu al piece 8 will fly out suiiiciently to throw o?? the latch ,11 and enable the parts 14 and 15 to make rubbing contact. lf the movement'is too slow, the centrifugal piece 8 will not reach the latch 11 and no current will pass inthe igniting circuit, and the parts 14 and 15 will remain out of contact.

What I claim and desire to secure by Letters Patent is 1. Magnet induction apparatus for electric blasting, com arising in combination, a rotary disk, a centrifugal piece pivoted to said disk, means restraining said centrifugal piece, a contact disposed in proximity to said centrifugal piece and adapted to close said circuit when said centrifugal piece has attained a 'certain speed, and a rack adapted to drive said disk, substantially as, and for the purpose, set forth.

i 2. Magnet induction'apparatus for electric blasting, comprising in combination, a rotary disk, a centrifugal piecepivoted to said disk, means restraining said centrifugal piece, a

ugal piece and adapted to close said circuit when said centrifugal piece has attained a certain speed, a rack adapted to drive said disk, and means to hold said rack in the bottom position, substantially as, and for the purpose, set forth.

' 3. M agnct induction apparatus for electric blasting, com rising in combination, a rotary tact piece 1 5 till the latch 11, engages behind,

contact disposed in proximity to said centrifdisk,a centri galpiece pivoted to saiddisk,

means restraining said centrifugal piece, contacts disposed apart in proximity to said centrifugal piece, means adapted'to bring saidcontacts together and close the circuit when 'said centrifugal piece has attained a certain speed and touches one of said contacts, and means enabling said ldisk to be operated by hand, substantially as set forth.

4. Magnet induction apparatus for electric blasting, com rising in combination, a rotary disk, a centriflgal' piece pivoted to said disk, means restraining said centrifugal piec'e, a contactdisposed in proximity to saidcentrifuglal piece and adapted to close thecircuit W en said centrifugal .piece has attained a certainspeed, a rack adapted to drivesaid disk, a notch in said rack, a bolt adapted to en alge in said notch, and a key tov move said bo t and thus release said rack, substantially as, and for the urpose, set forth.

5. Magnet in uction apparatus for electric blasting, comprising in combination, a rotary f disk, a centrifugal piece pivoted to said disk, means restraining said centrifugal piece, a contact disposed in proximity to said centrifu al picee and adapted to close the circuit Wien said centrifugal piece has attained a certain speed, a rack adapted to drive said disk, a notch in said rack, a bolt adapted to engage in said notch, a key to move said bolt and thus release said rack, a lever likewise adapted to b moved by said key and thus to move the contact and open the circuit closed by the action of said centrifugal piece, and a catch adapted to hold said contact in the open position, substantially as, and for the purpose, set forth.

' In Witness whereof I have hereunto signed my name this 23d day of November 1905, in the presence of two subscribing Witnesses.

JHAN N KRANNICHFELDT., In presence of- Bassin F. DUNLAP, LOUIS VANDORN. 

